/**
 * @file ext-connector.js
 *
 * @license MIT
 *
 * @copyright 2010 Alexis Deveria
 *
 */

 const name = "connector";

 const loadExtensionTranslation = async function (svgEditor) {
   let translationModule;
   const lang = svgEditor.configObj.pref('lang');
   try {
     // eslint-disable-next-line no-unsanitized/method
     translationModule = await import(`./locale/${lang}.js`);
   } catch (_error) {
     // eslint-disable-next-line no-console
     console.warn(`Missing translation (${lang}) for ${name} - using 'en'`);
     // eslint-disable-next-line no-unsanitized/method
     translationModule = await import(`./locale/en.js`);
   }
   svgEditor.i18next.addResourceBundle(lang, name, translationModule.default);
 };

 export default {
   name,
   async init(S) {
     const svgEditor = this;
     const { svgCanvas } = svgEditor;
     const { getElement, $id,$qq, mergeDeep } = svgCanvas;
     const { svgroot } = S;
     const addElem = svgCanvas.addSVGElementsFromJson;
     const selManager = S.selectorManager;
     await loadExtensionTranslation(svgEditor);

     let startX;
     let startY;
     let curLine;
     let startElem;
     let endElem;
     let seNs;
     let { svgContent } = S;
     let started = false;
     let connections = [];
     let selElems = [];

     /**
      *
      * @param {Float} x
      * @param {Float} y
      * @param {module:utilities.BBoxObject} bb
      * @param {Float} offset
      * @returns {module:math.XYObject}
      */
     const getBBintersect = (x, y, bb, offset) => {
       if (offset) {
         offset -= 0;
         bb = mergeDeep({}, bb);
         bb.width += offset;
         bb.height += offset;
         bb.x -= offset / 2;
         bb.y -= offset / 2;
       }

       const midX = bb.x + bb.width / 2;
       const midY = bb.y + bb.height / 2;
       const lenX = x - midX;
       const lenY = y - midY;

       const slope = Math.abs(lenY / lenX);

       let ratio;
       if (slope < bb.height / bb.width) {
         ratio = (bb.width / 2) / Math.abs(lenX);
       } else {
         ratio = lenY
           ? (bb.height / 2) / Math.abs(lenY)
           : 0;
       }

       return {
         x: midX + lenX * ratio,
         y: midY + lenY * ratio
       };
     };

     /**
     * @param {"start"|"end"} side
     * @param {Element} line
     * @returns {Float}
     */
     const getOffset = (side, line) => {
       const giveOffset = line.getAttribute('marker-' + side);

       // TODO: Make this number (5) be based on marker width/height
       const size = line.getAttribute('stroke-width') * 5;
       return giveOffset ? size : 0;
     };

     /**
     * @param {boolean} on
     * @returns {void}
     */
     const showPanel = (on) => {
       let connRules = $id('connector_rules');
       if (!connRules) {
         connRules = document.createElement('style');
         connRules.setAttribute('id', 'connector_rules');
         document.getElementsByTagName("head")[0].appendChild(connRules);
       }
       connRules.textContent = (!on ? '' : '#tool_clone, #tool_topath, #tool_angle, #xy_panel { display: none !important; }');
       if ($id('connector_panel'))
         $id('connector_panel').style.display = (on) ? 'block' : 'none';
     };

     /**
      * @param {Element} elem
      * @param {Integer|"end"} pos
      * @param {Float} x
      * @param {Float} y
      * @param {boolean} [setMid]
      * @returns {void}
     */
     const setPoint = (elem, pos, x, y, setMid) => {
       const pts = elem.points;
       const pt = svgroot.createSVGPoint();
       pt.x = x;
       pt.y = y;
       if (pos === 'end') { pos = pts.numberOfItems - 1; }
       // TODO: Test for this on init, then use alt only if needed
       try {
         pts.replaceItem(pt, pos);
       } catch (err) {
         // Should only occur in FF which formats points attr as "n,n n,n", so just split
         const ptArr = elem.getAttribute('points').split(' ');
         ptArr[pos] = x + ',' + y;
         elem.setAttribute('points', ptArr.join(' '));
       }

       if (setMid) {
         // Add center point
         const ptStart = pts.getItem(0);
         const ptEnd = pts.getItem(pts.numberOfItems - 1);
         setPoint(elem, 1, (ptEnd.x + ptStart.x) / 2, (ptEnd.y + ptStart.y) / 2);
       }
     };

     /**
     * @param {Float} diffX
     * @param {Float} diffY
     * @returns {void}
     */
     const updateLine = (diffX, diffY) => {
       const dataStorage = svgCanvas.getDataStorage();
       // Update line with element
       let i = connections.length;
       while (i--) {
         const conn = connections[i];
         const line = conn.connector;
         // const {elem} = conn;

         const pre = conn.is_start ? 'start' : 'end';
         // const sw = line.getAttribute('stroke-width') * 5;

         // Update bbox for this element
         const bb = dataStorage.get(line, pre + '_bb');
         bb.x = conn.start_x + diffX;
         bb.y = conn.start_y + diffY;
         dataStorage.put(line, pre + '_bb', bb);

         const altPre = conn.is_start ? 'end' : 'start';

         // Get center pt of connected element
         const bb2 = dataStorage.get(line, altPre + '_bb');
         const srcX = bb2.x + bb2.width / 2;
         const srcY = bb2.y + bb2.height / 2;

         // Set point of element being moved
         const pt = getBBintersect(srcX, srcY, bb, getOffset(pre, line));
         setPoint(line, conn.is_start ? 0 : 'end', pt.x, pt.y, true);

         // Set point of connected element
         const pt2 = getBBintersect(pt.x, pt.y, dataStorage.get(line, altPre + '_bb'), getOffset(altPre, line));
         setPoint(line, conn.is_start ? 'end' : 0, pt2.x, pt2.y, true);
       }
     };

     /**
     *
     * @param {Element[]} [elems=selElems] Array of elements
     * @returns {void}
     */
     const findConnectors = (elems = selElems) => {
       const dataStorage = svgCanvas.getDataStorage();
       // const connectors = svgContent.querySelectorAll('.se_connector');
       const connectors = svgContent.querySelectorAll('.se_connector');
       connections = [];

       // Loop through connectors to see if one is connected to the element
       Array.prototype.forEach.call(connectors, function (ethis) {
         let addThis;
         // Grab the ends
         const parts = [];
         [ 'start', 'end' ].forEach( (pos, i) => {
           const key = 'c_' + pos;
           let part = dataStorage.get(ethis, key);
           if (part === null || part === undefined) { // Does this ever return nullish values?
             part = document.getElementById(
               ethis.attributes['se:connector'].value.split(' ')[i]
             );
             dataStorage.put(ethis, 'c_' + pos, part.id);
             dataStorage.put(ethis, pos + '_bb', svgCanvas.getStrokedBBox([ part ]));
           } else part = $id(part);
           parts.push(part);
         }, ethis);

         for (let i = 0; i < 2; i++) {
           const cElem = parts[i];

           addThis = false;
           // The connected element might be part of a selected group
           const parents = svgCanvas.getParents(cElem.parentNode);
           Array.prototype.forEach.call(parents, function (el) {
             if (elems.includes(el)) {
               // Pretend this element is selected
               addThis = true;
             }
           });

           if (!cElem || !cElem.parentNode) {
             ethis.remove();
             continue;
           }
           if (elems.includes(cElem) || addThis) {
             const bb = svgCanvas.getStrokedBBox([ cElem ]);
             connections.push({
               elem: cElem,
               connector: ethis,
               is_start: (i === 0),
               start_x: bb.x,
               start_y: bb.y
             });
           }
         }
       });
     };

     /**
     * @param {Element[]} [elems=selElems]
     * @returns {void}
     */
     const updateConnectors = (elems) => {
       const dataStorage = svgCanvas.getDataStorage();
       // Updates connector lines based on selected elements
       // Is not used on mousemove, as it runs getStrokedBBox every time,
       // which isn't necessary there.
       findConnectors(elems);
       if (connections.length) {
         // Update line with element
         let i = connections.length;
         while (i--) {
           const conn = connections[i];
           const line = conn.connector;
           const { elem } = conn;

           // const sw = line.getAttribute('stroke-width') * 5;
           const pre = conn.is_start ? 'start' : 'end';

           // Update bbox for this element
           const bb = svgCanvas.getStrokedBBox([ elem ]);
           bb.x = conn.start_x;
           bb.y = conn.start_y;
           dataStorage.put(line, pre + '_bb', bb);
           /* const addOffset = */ dataStorage.get(line, pre + '_off');

           const altPre = conn.is_start ? 'end' : 'start';

           // Get center pt of connected element
           const bb2 = dataStorage.get(line, altPre + '_bb');
           const srcX = bb2.x + bb2.width / 2;
           const srcY = bb2.y + bb2.height / 2;

           // Set point of element being moved
           let pt = getBBintersect(srcX, srcY, bb, getOffset(pre, line));
           setPoint(line, conn.is_start ? 0 : 'end', pt.x, pt.y, true);

           // Set point of connected element
           const pt2 = getBBintersect(pt.x, pt.y, dataStorage.get(line, altPre + '_bb'), getOffset(altPre, line));
           setPoint(line, conn.is_start ? 'end' : 0, pt2.x, pt2.y, true);

           // Update points attribute manually for webkit
           if (navigator.userAgent.includes('AppleWebKit')) {
             const pts = line.points;
             const len = pts.numberOfItems;
             const ptArr = [];
             for (let j = 0; j < len; j++) {
               pt = pts.getItem(j);
               ptArr[j] = pt.x + ',' + pt.y;
             }
             line.setAttribute('points', ptArr.join(' '));
           }
         }
       }
     };

     // Do once
     (function () {
       const gse = svgCanvas.groupSelectedElements;

       svgCanvas.groupSelectedElements = function (...args) {

         svgCanvas.removeFromSelection(document.querySelectorAll('.se_connector'));
         return gse.apply(this, args);
       };

       const mse = svgCanvas.moveSelectedElements;

       svgCanvas.moveSelectedElements = function (...args) {
         const cmd = mse.apply(this, args);
         updateConnectors();
         return cmd;
       };

       seNs = svgCanvas.getEditorNS();
     }());

     /**
     * Do on reset.
     * @returns {void}
     */
     const init = () => {
       const dataStorage = svgCanvas.getDataStorage();
       // Make sure all connectors have data set
       const elements = svgContent.querySelectorAll('*');
       elements.forEach(function (curthis) {
         const conn = curthis.getAttributeNS(seNs, 'connector');
         if (conn) {
           curthis.setAttribute('class', 'se_connector');
           const connData = conn.split(' ');
           const sbb = svgCanvas.getStrokedBBox([ getElement(connData[0]) ]);
           const ebb = svgCanvas.getStrokedBBox([ getElement(connData[1]) ]);
           dataStorage.put(curthis, 'c_start', connData[0]);
           dataStorage.put(curthis, 'c_end', connData[1]);
           dataStorage.put(curthis, 'start_bb', sbb);
           dataStorage.put(curthis, 'end_bb', ebb);
           svgCanvas.getEditorNS(true);
         }
       });
     };

     return {
       name: svgEditor.i18next.t(`${name}:name`),
       callback() {
         const btitle = `${name}:langListTitle`;
         // eslint-disable-next-line no-unsanitized/property
         const buttonTemplate = `
         <se-button id="mode_connect" title="${btitle}" src="conn.svg"></se-button>
         `;
         svgCanvas.insertChildAtIndex($qq('.basicWrap .itemWrap'), buttonTemplate, 8)
         $id('mode_connect').addEventListener("click", () => {
           if (this.leftPanel.updateLeftPanel("ext-panning")) {
             svgCanvas.setMode('connector');
           }
         });
       },
       /* async */ addLangData({ _lang }) { // , importLocale: importLoc
         return {
           data: [
             { id: 'mode_connect', title: svgEditor.i18next.t(`${name}:langListTitle`) }
           ]
         };
       },
       initConnect:init,
       mouseDown(opts) {
         const dataStorage = svgCanvas.getDataStorage();
         const e = opts.event;
         startX = opts.start_x;
         startY = opts.start_y;
         const mode = svgCanvas.getMode();
         const { curConfig: { initStroke } } = svgEditor.configObj;
         svgContent = $id('svgcontent');

         if (mode === 'connector') {
           if (started) { return undefined; }

           const mouseTarget = e.target;

           const parents = svgCanvas.getParents(mouseTarget.parentNode);
           if (parents.includes(svgContent)) {
             // Connectable element

             // If child of foreignObject, use parent
             const fo = svgCanvas.getClosest(mouseTarget.parentNode, 'foreignObject');
             startElem = fo ? fo : mouseTarget;

             // Get center of source element
             const bb = svgCanvas.getStrokedBBox([ startElem ]);
             const x = bb.x + bb.width / 2;
             const y = bb.y + bb.height / 2;

             started = true;
             curLine = addElem({
               element: 'polyline',
               attr: {
                 id: svgCanvas.getNextId(),
                 points: (x + ',' + y + ' ' + x + ',' + y + ' ' + startX + ',' + startY),
                 stroke: '#' + initStroke.color,
                 'stroke-width': (!startElem.stroke_width || startElem.stroke_width === 0)
                   ? initStroke.width
                   : startElem.stroke_width,
                 fill: 'none',
                 opacity: initStroke.opacity,
                 style: 'pointer-events:none'
               }
             });
             dataStorage.put(curLine, 'start_bb', bb);
           }
           return {
             started: true
           };
         }
         if (mode === 'select') {
           findConnectors();
         }
         return undefined;
       },
       mouseMove(opts) {
         const dataStorage = svgCanvas.getDataStorage();
         const zoom = svgCanvas.getZoom();
         // const e = opts.event;
         const x = opts.mouse_x / zoom;
         const y = opts.mouse_y / zoom;

         const diffX = x - startX;
         const diffY = y - startY;

         const mode = svgCanvas.getMode();

         if (mode === 'connector' && started) {
           // const sw = curLine.getAttribute('stroke-width') * 3;
           // Set start point (adjusts based on bb)
           const pt = getBBintersect(x, y, dataStorage.get(curLine, 'start_bb'), getOffset('start', curLine));
           startX = pt.x;
           startY = pt.y;

           setPoint(curLine, 0, pt.x, pt.y, true);

           // Set end point
           setPoint(curLine, 'end', x, y, true);
         } else if (mode === 'select') {
           let slen = selElems.length;
           while (slen--) {
             const elem = selElems[slen];
             // Look for selected connector elements
             if (elem && dataStorage.has(elem, 'c_start')) {
               // Remove the "translate" transform given to move
               svgCanvas.removeFromSelection([ elem ]);
               elem.transform.baseVal.clear();
             }
           }
           if (connections.length) {
             updateLine(diffX, diffY);
           }
         }
       },
       mouseUp(opts) {
         const dataStorage = svgCanvas.getDataStorage();
         // const zoom = svgCanvas.getZoom();
         const e = opts.event;
         // , x = opts.mouse_x / zoom,
         // , y = opts.mouse_y / zoom,
         let mouseTarget = e.target;

         if (svgCanvas.getMode() !== 'connector') {
           return undefined;
         }
         const fo = svgCanvas.getClosest(mouseTarget.parentNode, 'foreignObject');
         if (fo) { mouseTarget = fo; }

         const parents = svgCanvas.getParents(mouseTarget.parentNode);

         if (mouseTarget === startElem) {
           // Start line through click
           started = true;
           return {
             keep: true,
             element: null,
             started
           };
         }
         if (parents.indexOf(svgContent) === -1) {
           // Not a valid target element, so remove line
           if (curLine)
             curLine.remove();
           started = false;
           return {
             keep: false,
             element: null,
             started
           };
         }
         // Valid end element
         endElem = mouseTarget;

         const startId = (startElem) ? startElem.id : '';
         const endId = (endElem) ? endElem.id : '';
         const connStr = startId + ' ' + endId;
         const altStr = endId + ' ' + startId;
         // Don't create connector if one already exists
         const dupe = Array.prototype.filter.call(svgContent.querySelectorAll('.se_connector'), function (aThis) {
           const conn = aThis.getAttributeNS(seNs, 'connector');
           if (conn === connStr || conn === altStr) { return true; }
           return false;
         });
         if (dupe.length) {
           curLine.remove();
           return {
             keep: false,
             element: null,
             started: false
           };
         }

         const bb = svgCanvas.getStrokedBBox([ endElem ]);

         const pt = getBBintersect(startX, startY, bb, getOffset('start', curLine));
         setPoint(curLine, 'end', pt.x, pt.y, true);
         dataStorage.put(curLine, 'c_start', startId);
         dataStorage.put(curLine, 'c_end', endId);
         dataStorage.put(curLine, 'end_bb', bb);
         seNs = svgCanvas.getEditorNS(true);
         curLine.setAttributeNS(seNs, 'se:connector', connStr);
         curLine.setAttribute('class', 'se_connector');
         curLine.setAttribute('opacity', 1);
         svgCanvas.addToSelection([ curLine ]);
         svgCanvas.moveToBottomSelectedElement();
         selManager.requestSelector(curLine).showGrips(false);
         started = false;
         return {
           keep: true,
           element: curLine,
           started
         };
       },
       selectedChanged(opts) {
         const dataStorage = svgCanvas.getDataStorage();
         // TODO: Find better way to skip operations if no connectors are in use
         if (!svgContent.querySelectorAll('.se_connector').length) { return; }

         if (svgCanvas.getMode() === 'connector') {
           svgCanvas.setMode('select');
         }

         // Use this to update the current selected elements
         selElems = opts.elems;

         let i = selElems.length;
         while (i--) {
           const elem = selElems[i];
           if (elem && dataStorage.has(elem, 'c_start')) {
             selManager.requestSelector(elem).showGrips(false);
             if (opts.selectedElement && !opts.multiselected) {
               // TODO: Set up context tools and hide most regular line tools
               showPanel(true);
             } else {
               showPanel(false);
             }
           } else {
             showPanel(false);
           }
         }
         updateConnectors();
       },
       sourceChanged(opts) {
         const dataStorage = svgCanvas.getDataStorage();
         let elem = opts.elems[0];
         if (!elem) return;
         if (elem.tagName === 'svg' && elem.id === 'svgcontent') {
           // Update svgContent (can change on import)
           svgContent = elem;
           init();
         }

         // Has marker, so change offset
         if (
           elem.getAttribute('marker-start') ||
           elem.getAttribute('marker-mid') ||
           elem.getAttribute('marker-end')
         ) {
           const start = elem.getAttribute('marker-start');
           const mid = elem.getAttribute('marker-mid');
           const end = elem.getAttribute('marker-end');
           curLine = elem;
           dataStorage.put(elem, 'start_off', Boolean(start));
           dataStorage.put(elem, 'end_off', Boolean(end));

           if (elem.tagName === 'line' && mid) {
             // Convert to polyline to accept mid-arrow

             const x1 = Number(elem.getAttribute('x1'));
             const x2 = Number(elem.getAttribute('x2'));
             const y1 = Number(elem.getAttribute('y1'));
             const y2 = Number(elem.getAttribute('y2'));
             const { id } = elem;

             const midPt = (' ' + ((x1 + x2) / 2) + ',' + ((y1 + y2) / 2) + ' ');
             const pline = addElem({
               element: 'polyline',
               attr: {
                 points: (x1 + ',' + y1 + midPt + x2 + ',' + y2),
                 stroke: elem.getAttribute('stroke'),
                 'stroke-width': elem.getAttribute('stroke-width'),
                 'marker-mid': mid,
                 fill: 'none',
                 opacity: elem.getAttribute('opacity') || 1
               }
             });
             elem.insertAdjacentElement('afterend', pline);
             elem.remove();
             svgCanvas.clearSelection();
             pline.id = id;
             svgCanvas.addToSelection([ pline ]);
             elem = pline;
           }
         }
         // Update line if it's a connector
         if (elem.getAttribute('class') === 'se_connector') {
           const start = getElement(dataStorage.get(elem, 'c_start'));
           updateConnectors([ start ]);
         } else {
           updateConnectors();
         }
       },
       elementChanged(opts) {
         const dataStorage = svgCanvas.getDataStorage();
         let elem = opts.elems[0];
         if (!elem) return;
         if (elem.tagName === 'svg' && elem.id === 'svgcontent') {
           // Update svgContent (can change on import)
           svgContent = elem;
           init();
         }

         // Has marker, so change offset
         if (
           elem.getAttribute('marker-start') ||
           elem.getAttribute('marker-mid') ||
           elem.getAttribute('marker-end')
         ) {
           const start = elem.getAttribute('marker-start');
           const mid = elem.getAttribute('marker-mid');
           const end = elem.getAttribute('marker-end');
           curLine = elem;
           dataStorage.put(elem, 'start_off', Boolean(start));
           dataStorage.put(elem, 'end_off', Boolean(end));

           if (elem.tagName === 'line' && mid) {
             // Convert to polyline to accept mid-arrow

             const x1 = Number(elem.getAttribute('x1'));
             const x2 = Number(elem.getAttribute('x2'));
             const y1 = Number(elem.getAttribute('y1'));
             const y2 = Number(elem.getAttribute('y2'));
             const { id } = elem;

             const midPt = (' ' + ((x1 + x2) / 2) + ',' + ((y1 + y2) / 2) + ' ');
             const pline = addElem({
               element: 'polyline',
               attr: {
                 points: (x1 + ',' + y1 + midPt + x2 + ',' + y2),
                 stroke: elem.getAttribute('stroke'),
                 'stroke-width': elem.getAttribute('stroke-width'),
                 'marker-mid': mid,
                 fill: 'none',
                 opacity: elem.getAttribute('opacity') || 1
               }
             });
             elem.insertAdjacentElement('afterend', pline);
             elem.remove();
             svgCanvas.clearSelection();
             pline.id = id;
             svgCanvas.addToSelection([ pline ]);
             elem = pline;
           }
         }
         // Update line if it's a connector
         if (elem.getAttribute('class') === 'se_connector') {
           const start = getElement(dataStorage.get(elem, 'c_start'));
           updateConnectors([ start ]);
         } else {
           updateConnectors();
         }
       },
       IDsUpdated(input) {
         const remove = [];
         input.elems.forEach(function (elem) {
           if ('se:connector' in elem.attr) {
             elem.attr['se:connector'] = elem.attr['se:connector'].split(' ')
               .map(function (oldID) { return input.changes[oldID]; }).join(' ');

             // Check validity - the field would be something like 'svg_21 svg_22', but
             // if one end is missing, it would be 'svg_21' and therefore fail this test
             if (!(/. ./).test(elem.attr['se:connector'])) {
               remove.push(elem.attr.id);
             }
           }
         });
         return { remove };
       },
       toolButtonStateUpdate(opts) {
         const button = document.getElementById('mode_connect');
         if (opts.nostroke && button.pressed === true) {
           svgEditor.clickSelect();
         }
         button.disabled = opts.nostroke;
       }
     };
   }
 };
